Increase selftest_irsensor() filament nozzle unload temperature to ABS.

Resume nozzle temperature immediately after unload.

Firmware/ultralcd.cpp

@@ -7026,12 +7026,14 @@ static bool selftest_irsensor()
         float m_temp;
         uint8_t m_extruder;
     };
-
-    TempBackup tempBackup;
-    setTargetHotend(PLA_PREHEAT_HOTEND_TEMP,active_extruder);
-    mmu_wait_for_heater_blocking();
-    uint8_t progress = lcd_selftest_screen(9, 0, 1, true, 0);
-    mmu_filament_ramming();
+    uint8_t progress;
+    {
+        TempBackup tempBackup;
+        setTargetHotend(ABS_PREHEAT_HOTEND_TEMP,active_extruder);
+        mmu_wait_for_heater_blocking();
+        progress = lcd_selftest_screen(9, 0, 1, true, 0);
+        mmu_filament_ramming();
+    }
     progress = lcd_selftest_screen(9, progress, 1, true, 0);
     mmu_command(MMU_CMD_U0);
     manage_response(false, false);